On July 12, 2007, EPA published three notices in the Federal Register concerning the Agency’s proposal for managing nanoscale chemical substances under the Toxic Substances Control Act (“TSCA”). The first notice announced the availability of two draft documents - a concept paper describing the Agency’s Nanoscale Materials Stewardship Program (“NMSP” or “Stewardship Program”), and a guidance document clarifying the TSCA Inventory status of nanoscale chemical substances. The second Federal Register notice solicited comments on the specific information collection aspects of the NMSP, including the preferred reporting form. The third and final notice announced a public meeting that the Agency will hold on August 2, 2007, to receive public comments on the Stewardship Program. Publication of the three draft documents resolves longstanding uncertainty regarding EPA’s near-term management of nanoscale chemical substances under TSCA.

Nanoscale Materials Stewardship Program

EPA requested comments on two draft documents specific to the NMSP. The first is the “Concept Paper for the Nanoscale Materials Stewardship Program under TSCA,” which outlines the voluntary reporting program that EPA is proposing. The second document is a draft of the Information Collection Request (“ICR”) that EPA must submit to the Office of Management and Budget (“OMB”) for approval prior to soliciting information from the regulated community through the NMSP. The ICR details the information collection aspects of the Stewardship Program and includes a draft of the preferred reporting form. The reporting form is patterned on the Premanufacture Notice (“PMN”) that companies submit in advance of manufacturing or importing new chemical substances.

Both the concept paper and the ICR explain the scope and operation of the NMSP. According to these documents, EPA intends to implement a voluntary program with two tiers – a “basic” program for a large number of chemical substances, and an “in-depth” program for a smaller subset of substances. The NMSP is primarily designed to collect data from manufacturers, importers, and processors of “engineered nanoscale materials” considered “existing” chemical substances for TSCA regulatory purposes. However, EPA will accept information on “new” chemical substances, provided participants also comply with the PMN regulations. For purposes of the Stewardship Program, “engineered nanoscale materials” include “any particle, substance, or material that has been engineered to have one or more dimensions in the nanoscale.” “Engineered” materials are those purposefully produced at the nanoscale, which is defined as “the scale … [that] is generally, but not exclusively, below 100 nm and above 1 nm.”

Through the basic program, a participant will provide all information that is “known or reasonably ascertainable” regarding material characterization, hazards, uses, potential exposures and risk management practices for a particular engineered nanoscale material. The range of data requested is similar to that currently sought through the PMN program although additional data elements are included to facilitate an understanding of the potential risks attending commercialization of these materials. EPA is not requiring a basic program participant to generate any new data. However, a basic program participant must agree to implement a risk management program that includes consideration of engineered nanoscale materials and relevant practices that the participant and EPA identify.

The “in-depth” program will focus on a limited set of representative materials having significant potential to further the Agency’s understanding and capacity to use TSCA to manage potential risks. Participation in the in-depth program is also voluntary. EPA will select materials based on mutual interest of the Agency and a participant (either a consortia or an individual), with input from stakeholders. The extent of commercial use of a particular material may influence EPA’s final selection. In contrast to a basic program participant, an in-depth participant will consult with EPA to identify and fill outstanding data needs, including those related to material characterization, hazard, fate and transport, as well as the effectiveness of worker training, personal protective equipment, and engineering controls. In theory, the final suite of information will enable EPA and the participant to perform a risk assessment of a material across its lifecycle and ultimately develop an appropriate set of risk management measures.

EPA intends to use the data generated through both programs to enhance its understanding of nanoscale materials that are currently under production and to determine whether and how such materials could pose a risk to human health and the environment. Should data suggest that particular material poses a potential for unreasonable risk to human health or the environment, EPA will determine appropriate protective measures to mitigate that risk. In addition, EPA intends to share non-confidential information with a broad range of stakeholders, including researchers, state and local governments, and intergovernmental organizations such as the Organization for Economic Cooperation and Development (“OECD”). Confidential Business Information (“CBI”) will be afforded the protections available under 15 U.S.C. § 2613 and 40 C.F.R. Parts 2 and 720. To facilitate transparency and broad stakeholder input, however, EPA is encouraging participants to be conservative in their assertion of CBI protections.

TSCA Inventory Status of Nanoscale Chemical Substances

EPA also announced the availability of a draft version of a long-anticipated guidance document on a topic that has been the subject of intense debate in recent years. The draft document sets out the methodology that EPA will use to determine whether a nanoscale chemical substance is “new” or “existing” for TSCA Inventory purposes. The document affirms that EPA will make this determination through a case-by-case evaluation of a substance’s “molecular identity” as that term has been historically understood. Accordingly, EPA will continue to evaluate the structural and compositional features of a substance, which, in the past, have included the types and numbers of atoms in a molecule, the types and number of chemical bonds, and the connectivity and spatial arrangement of atoms in a molecule.

Despite calls by various interest groups, EPA declined to interpret the term “molecular identity” broadly to encompass the physical form of a substance, such as its particle size. EPA also declined to evaluate the Inventory status of a chemical substance based on its physical or chemical properties. A broad interpretation would have deviated from the Agency’s historical practice and possibly subjected numerous additional substances to PMN review. EPA’s guidance thus clarifies that a single Inventory listing encompasses both the nanoscale and macroscale versions of a chemical substance. Consequently, if a nanoscale version of chemical substance has the same “molecular identity” as a chemical already listed on the TSCA Inventory, EPA will treat the nanoscale version as “existing,” even if the original Inventory listing was based on a macro, or bulk-scale version of the chemical.

To facilitate future Inventory determinations, EPA encouraged companies to contact the New Chemicals Program Office to arrange a pre-notice consultation. The Agency also expressed its intention to include a sufficient number of data elements in any future Inventory listings of nanoscale substances to enable an unambiguous identification of their molecular identities. If necessary, EPA will provide interim nomenclature guidance while more formal nomenclature conventions are developed. Considering the variety of materials that nanotechnology may enable, close coordination with EPA may be required for the foreseeable future.